Process for preparation of fuels and lubes in a single integrated hydrocracking system

Abstract

An integrated distillate hydrocracking process produces one or more fuel products and one or more lube products from a first reaction stage. Heavy fractions from the first stage, which are not recovered as lube products, are cracked to fuels in a second reaction stage. This invention is intended to provide a full range of lube streams, over a wide viscosity range and a wide viscosity index range, from a fuels hydrocracker, in addition to high yields of high quality fuels.

What is claimed is:  
     
       1. An integrated process for producing both fuels and lubricating oil products from a single integrated hydrocracking system, which produces high yields of high quality fuels, while maintaining flexibility for selecting the desired product properties for the lubricating oil products recovered from the process, comprising the steps of: 
       a. contacting a liquid hydrocarbon feedstock with hydrogen over a first catalyst in a hydroprocessing zone which may be operated at either hydrotreating or hydrocracking conditions, which is operated at conditions effective to remove impurities contained in the feedstock, to yield a first effluent containing a normally liquid fraction;  
       b. separating the normally liquid fraction from the first effluent by boiling point range in an atmospheric separation zone to produce a first fuel product and a heavy fraction;  
       c. separating the heavy fraction of step (b) in a vacuum separation zone to yield a first lubricating oil product and a bottom fraction;  
       d. contacting at least a portion of the bottom fraction of step (c) with a second catalyst in a hydrocracking zone operated at conditions effective to hydrocrack the bottom fraction, to yield a second effluent;  
       e. separating the second effluent of step (d) by boiling point range to yield an overhead stream and a recycle stream: and  
       f. recycling the recycle stream of step (e) to the hydrocracking zone.  
     
     
       2. The process according to  claim 1  wherein at least a portion of the bottom fraction is recovered as a second lubricating oil product. 
     
     
       3. The process according to  claim 1  further producing a second fuel product. 
     
     
       4. The process according to  claim 1  wherein some of the first lubricating oil product is combined with the bottom fraction for contacting the catalyst in the hydrocracking zone. 
     
     
       5. The process according to  claim 1  wherein the first lubricating oil product is derived from the first effluent only. 
     
     
       6. The process according to  claim 1  wherein the first lubricating oil product has a viscosity, measured at 100° C. between about 2 cSt and about 60 cSt, and a viscosity index of greater than 90. 
     
     
       7. The process according to  claim 2 , wherein the second lubricating oil product has a viscosity, measured at 1000 between about 2 cSt and about 60 cSt, and a viscosity index of greater than 90. 
     
     
       8. The process according to  claim 1  wherein the overhead stream boils in a temperature range that is within or below the middle distillate range. 
     
     
       9. The process according to  claim 1  wherein the liquid hydrocarbon feedstock is a vacuum gas oil. 
     
     
       10. The process according to  claim 1  wherein the liquid hydrocarbon feed stock is a synthetic product from a Fischer Tropsch process. 
     
     
       11. The process according to  claim 10  wherein the liquid hydrocarbon feedstock is a wax from a Fischer Tropsch process, the wax having a boiling point of greater than about 650° F. 
     
     
       12. An integrated process for producing both fuels and lubricating oil products from a single integrated hydrocracking system, which comprises the steps of: 
       a. contacting a liquid hydrocarbon feedstock with hydrogen over a first catalyst in a hydroprocessing zone, which may be operated at either hydrotreating or hydrocracking conditions, and is operated at conditions effective to remove impurities contained in the feedstock, to yield a first effluent containing a normally liquid fraction, comprising a fuel product having a normal boiling point below the normal boiling point of the liquid hydrocarbon feedstock;  
       b. separating the first effluent from the hydroprocessing zone in an atmospheric separation zone to yield a first fuel product and a heavy fraction;  
       c. separating the heavy fraction in a vacuum separation zone to yield a second fuel product, a first lubricating oil product and a bottom fraction;  
       d. combining at least a portion of the first lubricating oil product with the bottom fraction to yield a hydrocracker feed stream;  
       e. contacting the hydrocracker feedstream with a second catalyst in a hydrocracking zone operated at conditions effective to hydrocrack the hydrocracker feedstream to yield a second effluent;  
       f. separating the second effluent to yield an overhead stream and a recycle stream; and  
       g. combining the overhead stream with the first effluent for separation in the atmospheric separation zone.  
     
     
       13. The process according to  claim 12  further comprising recycling the recycle stream to the hydrocracking zone. 
     
     
       14. The process according to  claim 12  further comprising recovering at least a portion of the bottom fraction as a second lubricating oil product. 
     
     
       15. The process according to  claim 12  further comprising recovering at least a portion of the recycle stream as a third lubricating oil product. 
     
     
       16. The process according to  claim 12  wherein the first lubricating oil product has a viscosity, measured at 1000, between about 2 cSt and about 60 cSt, and a viscosity index of greater than 90. 
     
     
       17. The process according to  claim 13  wherein the second lubricating oil product has a viscosity, measured at 1000, between about 2 cSt and about 60 cSt, and a viscosity index of greater than 90. 
     
     
       18. The process according to  claim 13  wherein the third lubricating oil product has a viscosity, measured at 1000, between about 2 cSt and about 10 cSt, and a viscosity index above about 100.